Most of proteins are synthesized in the endoplasmic reticulum (ER) in cells and appropriately folded to gain their proper functions. When cells are exposed to an abnormal environment, the function of the ER may be disrupted and a large amount of defective proteins may be produced in the ER. Cells have some proteins which can detect such abnormal situations as above. When the abnormal situation has been detected, the cells can actively repair or degrade the abnormal proteins, thereby protecting themselves from toxicity of the abnormal proteins. BBF2H7 has been reported as a protein involved in this mechanism. (Non-Patent Literature 1).
Involvement of BBF2H7 in cartilage formation has been suggested. It has been reported that in chondrocytes of BBF2H7-knockout mice cartilage matrix proteins are not secreted extracellularly and accumulate in the ER (Non-Patent Literature 2). It also has been reported that BBF2H7 promotes synthesis of Sec23a, a protein essential for formation of the transport vesicles (Non-Patent Literature 2). Furthermore, it has been reported that BBF2H7 is subjected to regulated intramembrane proteolysis by Site-1 protease (Non-Patent Literature 3).
On the other hand, abnormalities in hedgehog signaling have been reported in various cancers including, for example, basal cell carcinoma, neuroectodermal tumors such as medullablastoma, meningioma, hemangioma, glioblastoma, pancreatic adenocarcinoma, squamous lung carcinoma, small-cell lung carcinoma, non-small cell lung carcinoma, chondrosarcoma, breast cancer, rhabdomyosarcoma, oesophageal cancer, stomach cancer, biliary tract cancer, renal cancer, and thyroid cancer (Patent Literature 1). Actually, vismodegib, an inhibitor of hedgehog signaling, has been approved for treating basal cell carcinoma in countries including the United States.